warning JEEP XJ 1995 Service And Manual PDF

The gauge needle moves as the movable permanent
magnet aligns itself to the changing magnetic fields
created around it by the electromagnets.
COOLANT TEMPERATURE GAUGE
The coolant temperature gauge gives an indication
of engine coolant temperature. The coolant tempera-
ture sending unit is a thermistor that changes elec-
trical resistance with changes in engine coolant
temperature. High sending unit resistance causes
low coolant temperature readings. Low resistance
causes high coolant temperature readings. Sending
unit resistance values are shown in a chart in Spec-
ifications.
FUEL GAUGE
The fuel gauge gives an indication of the level of
fuel in the fuel tank. The fuel gauge sending unit has
a float attached to a swing-arm in the fuel tank. The
float moves up or down within the fuel tank as fuel
level changes. As the float moves, an electrical con-
tact on the swing-arm wipes across a resistor coil,
which changes sending unit resistance. High sending
unit resistance causes high fuel level readings. Low
resistance causes low fuel level readings. Sending
unit resistance values are shown in a chart in Spec-
ifications.
OIL PRESSURE GAUGE
The oil pressure gauge gives an indication of en-
gine oil pressure. The combination oil pressure send-
ing unit contains a flexible diaphragm. The
diaphragm moves in response to changes in engine
oil pressure. As the diaphragm moves, sending unit
resistance increases or decreases. High resistance on
the gauge side of the sending unit causes high oil
pressure readings. Low resistance causes low oil
pressure readings. Sending unit resistance values are
shown in a chart in Specifications.
SPEEDOMETER/ODOMETER
The speedometer/odometer give an indication of ve-
hicle speed and travel distance. The speedometer re-
ceives a vehicle speed pulse signal from the Vehicle
Speed Sensor (VSS). An electronic integrated circuit
contained within the speedometer reads and analyzes
the pulse signal. It then adjusts the ground path re-
sistance of one electromagnet in the gauge to control
needle movement. It also sends signals to an electric
stepper motor to control movement of the odometer
number rolls. Frequency values for the pulse signal
are shown in a chart in Specifications.
The VSS is mounted to an adapter near the trans-
fer case output shaft. The sensor is driven through
the adapter by a speedometer pinion gear. The
adapter and pinion vary with transmission, axle ratio
and tire size. Refer to Group 21 - Transmission and
Transfer Case for more information.
TACHOMETER
The tachometer gives an indication of engine speed
in Revolutions-Per-Minute (RPM). With the engine
running, the tachometer receives an engine speed
pulse signal from the Powertrain Control Module
(PCM). An electronic integrated circuit contained
within the tachometer reads and analyzes the pulse
signal. It then adjusts the ground path resistance of
one electromagnet in the gauge to control needle
movement. Frequency values for the pulse signal are
shown in a chart in Specifications.
TRIP ODOMETER
The trip odometer is driven by the same electronic
integrated circuit as the speedometer/odometer. How-
ever, by depressing the trip odometer reset knob on
the face of the speedometer, the trip odometer can be
reset to zero. The trip odometer is serviced only as a
part of the speedometer/odometer gauge assembly.
VOLTMETER
The voltmeter is connected in parallel with the bat-
tery. With the ignition switch ON, the voltmeter in-
dicates battery or generator output voltage,
whichever is greater.
INDICATOR LAMPS
All indicator lamps, except the four-wheel drive in-
dicator, are located in the main cluster tell-tale area
above the steering column opening. Each of the
lamps is served by the main cluster printed circuit
and cluster connector. The four-wheel drive indicator
lamp is located in the gauge package cluster and is
served by the gauge package printed circuit and clus-
ter connector.
Up to eleven indicator lamps can be found in the
tell-tale area of the main cluster. These lamps are ar-
ranged in two rows, with six lamps in the upper row
and five lamps in the lower row.
ANTI-LOCK BRAKE SYSTEM LAMP
The Anti-Lock Brake System (ABS) lamp is
switched to ground by the ABS module. The module
lights the lamp when the ignition switch is turned to
the START position as a bulb test. The lamp will
stay on for 3 to 5 seconds after vehicle start-up to in-
dicate a system self-test is in process. If the lamp re-
mains on after start-up, or comes on and stays on
while driving, it may indicate that the ABS module
has detected a system malfunction or that the system
has become inoperative. Refer to Group 5 - Brakes
for more information.
BRAKE WARNING LAMP
The brake warning lamp warns the driver that the
parking brake is applied or that the pressures in the
two halves of the split brake hydraulic system are
unequal. With the ignition switch turned ON, battery
JINSTRUMENT PANEL AND GAUGESÐYJ 8E - 25

voltage is supplied to one side of the indicator bulb. A
ground path for the bulb is provided by 3 switches.
The bulb will light when:
²the brake warning switch is closed (indicating un-
equal brake system hydraulic pressures possibly due
to brake fluid leakage)
²the ignition switch is in the START position (bulb
test)
²the parking brake switch is closed (parking brake
is applied).
Refer to Group 5 - Brakes for more information.
FOUR-WHEEL DRIVE INDICATOR LAMP
This lamp lights when the transfer case is engaged
in the 4H or 4L position. Voltage is supplied to one
side of the indicator bulb. A switch on the front axle
disconnect housing is connected to the other side of
the indicator bulb. When the switch is closed, a path
to ground is provided and the indicator bulb lights.
HEADLAMP HIGH BEAM INDICATOR LAMP
The high beam indicator lamp is controlled by the
headlamp dimmer switch. One side of the indicator
bulb is grounded at all times. The other side of the
bulb receives battery feed through the contacts of the
dimmer switch when the turn signal switch lever is
actuated to turn the headlamp high beams on. Refer
to Group 8L - Lamps for more information.
MALFUNCTION INDICATOR LAMP
The CHECK ENGINE or Malfunction Indicator
Lamp (MIL) lights each time the ignition switch is
turned ON, and stays on for 3 seconds as a bulb test.
If the Powertrain Control Module (PCM) receives an
incorrect signal or no signal from certain fuel or
emission system related circuits or components, the
lamp is turned on. This will indicate that the PCM
has recorded a Diagnostic Trouble Code (DTC) in
electronic memory for a circuit or component mal-
function. Refer to Group 14 - Fuel System for more
information.
SEAT BELT REMINDER LAMP
The seat belt reminder lamp lights for 4 to 8 sec-
onds after the ignition switch is turned to the ON po-sition. A timer in the chime/buzzer module controls
ignition-switched battery feed to the lamp. Refer to
Group 8U - Chime/Buzzer Warning Systems for more
information.
TURN SIGNAL INDICATOR LAMPS
The left and right turn signal indicator lamps are
controlled by the turn signal and hazard warning
switches. One side of the bulb for each lamp is
grounded at all times. The other side of the bulb re-
ceives battery feed through the contacts of the turn
signal switch, when the turn signal lever or hazard
warning button are actuated. Refer to Group 8J -
Turn Signal and Hazard Warning Systems for more
information.
UPSHIFT INDICATOR LAMP
Vehicles equipped with manual transmissions have
an optional upshift indicator lamp. Ground feed for
the lamp is switched by the Powertrain Control Mod-
ule (PCM). The lamp lights to indicate when the
driver should shift to the next highest gear for best
fuel economy. The PCM will turn the lamp off after 3
to 5 seconds if the upshift is not performed. The lamp
will remain off until the vehicle stops accelerating
and is brought back to the range of lamp operation,
or until the transmission is shifted into another gear.
The indicator lamp is normally on when the igni-
tion switch is turned ON and is turned off when the
engine is started. The lamp will be turned on during
vehicle operation according to engine speed and load.
CLUSTER ILLUMINATION LAMPS
All cluster illumination lamps receive battery feed
from the instrument lamps fuse in the fuseblock
module through the panel dimmer switch. When the
park or headlamps are on, the cluster illumination
lamps light. Illumination brightness can be adjusted
by rotating the panel dimmer thumb-wheel, which is
next to the headlamp switch.
8E - 26 INSTRUMENT PANEL AND GAUGESÐYJJ

INDICATOR LAMPS
If an individual indicator lamp is inoperative, see
the diagnostic procedure under the heading for that
lamp. If more than one indicator lamp or a combina-
tion of lamps and gauges in the main cluster or the
gauge package cluster is inoperative, see Gauges in
this section for diagnosis.
ANTI-LOCK BRAKE SYSTEM LAMP
The diagnosis found here addresses an inoperative
lamp condition. If the ABS lamp stays on with the ig-
nition switch in the ON position, or comes on and
stays on while driving, refer to Group 5 - Brakes for
diagnosis. If no ABS problem is found, the following
procedure will help locate a short or open in the ABS
lamp circuit.
(1) Disconnect battery negative cable. Remove left
instrument cluster bezel and main cluster assembly.
Disconnect ABS control module connector.
(2) Install a jumper wire between cavity 6 of clus-
ter connector and a good ground. Connect battery
negative cable. Turn ignition switch to ON. Lamp
should light. If OK, remove jumper wire and go to
next step. If not OK, replace bulb.
(3) Turn ignition switch to OFF. Disconnect battery
negative cable and unplug cluster connector. Check
for continuity between cavity 6 of cluster connector
and a good ground. There should be no continuity. If
OK, go to next step. If not OK, repair short circuit as
required.
(4) Check continuity between cavity 6 of cluster
connector and cavity 52 of ABS control module con-
nector (Fig. 6). There should be continuity. If OK, re-
fer to Group 5 - Brakes for diagnosis of ABS control
module. If not OK, repair open circuit as required.
BRAKE WARNING LAMP
The diagnosis found here addresses an inoperative
lamp condition. If the brake warning lamp stays on
with the ignition switch in the ON position and the
parking brake released, refer to Group 5 - Brakes for
diagnosis. If no service brake or parking brake prob-
lem is found, the following procedure will help locate
a short circuit or faulty switch.
(1) Unplug parking brake switch connector. Turn
ignition switch to START position. Lamp should
light. Release ignition switch to ON position. Lamp
should go off. If OK, go to step 10. If not OK, go to
next step.
(2) Unplug brake warning switch connector. Install
a jumper wire between two cavities of connector.
Turn ignition switch to START. Lamp should light.
Remove jumper wire and lamp should go off. If OK,
replace brake warning switch. If not OK, remove
jumper wire and go to next step.
(3) Turn ignition switch to ON position. Install a
jumper wire between brake warning switch connectorcavity for circuit G9 and a good ground. Lamp should
light. If OK, go to step 5. If not OK, go to next step.
(4) Turn ignition switch to OFF. Remove jumper
wire and disconnect battery negative cable. Remove
left instrument cluster bezel and main cluster. Install
a jumper wire between cavity 1 of cluster connector
and a good ground. Connect battery negative cable
and turn ignition switch to ON. Lamp should light. If
OK, repair open in circuit to brake warning switch. If
not OK, replace bulb.
(5) Turn ignition switch to OFF and remove
jumper wire. Disconnect battery negative cable.
Check for continuity between brake warning switch
connector cavity for circuit G11 and a good ground
with ignition switch in START position. There should
be continuity. If not OK, go to next step.
(6) Turn ignition switch to OFF and remove
jumper wire. Unplug ignition switch connectors.
Check for continuity between ignition switch connec-
tor cavity for G11 circuit and a good ground. There
should be no continuity. If OK, go to next step. If not
OK, repair short circuit between ignition switch and
brake warning switch connectors as required.
(7) Check for continuity between ignition switch
connector cavity for G11 circuit and brake warning
switch connector cavity for G11 circuit. There should
be continuity. If OK, go to next step. If not OK, re-
pair open circuit as required.
(8) Check for continuity between metal steering
column jacket and a good ground. There should be
continuity. If OK, go to next step. If not OK, refer to
Group 19 - Steering to check steering column ground
clip installation.
Fig. 6 ABS Control Module Connector
8E - 32 INSTRUMENT PANEL AND GAUGESÐYJJ

(9) Turn ignition switch to START position and
hold there. Check for continuity between terminal for
circuit G11 of ignition switch and a good ground.
There should be continuity. If not OK, replace igni-
tion switch.
(10) Unplug brake warning switch connector.
Check for continuity between parking brake switch
connector and a good ground. There should be no
continuity. If OK, go to next step. If not OK, repair
short circuit as required.
(11) Check for continuity between parking brake
switch connector and brake warning switch connector
cavity for circuit G11. There should be continuity. If
OK, replace parking brake switch. If not OK, repair
open circuit to brake warning switch as required.
FOUR-WHEEL DRIVE INDICATOR LAMP
(1) Apply parking brake, start engine, vehicle in
4WD Lock or 4WD.
(2) Unplug switch and touch harness side of wire
to ground. Lamp should light. If OK, check switch
operation, replace if bad. If bulb is OK, repair open
to indicator.
HEADLAMP HIGH BEAM INDICATOR LAMP
(1) Check that headlamp high beams are func-
tional. If OK, go to next step. If not OK, refer to
Group 8L - Lamps for diagnosis of headlamp system.
(2) Disconnect battery negative cable. Remove left
instrument cluster bezel and main cluster assembly.
Unplug cluster connector. Connect battery negative
cable. Turn headlamps on and select high beam.
Check for battery voltage at cavity 17 of cluster con-
nector. If OK, replace indicator bulb. If not OK, re-
pair circuit to headlamp dimmer switch as required.
MALFUNCTION INDICATOR LAMP
The diagnosis found here addresses an inoperative
lamp condition. If the lamp comes on and stays on
with engine running, refer to Group 14 - Fuel System
for diagnosis. If no fuel or emission system problem
is found, the following procedure will help locate a
short or open in the lamp circuit.
(1) Disconnect battery negative cable. Unplug PCM
connector. Install a jumper wire from cavity 32 of
PCM connector (Fig. 5) to a good ground. Connect
battery negative cable. Turn ignition switch to ON.
Lamp should light. Remove jumper wire and lamp
should go OFF. If OK, refer to Powertrain Diagnostic
Procedures to check PCM. If not OK, go to next step.
(2) Turn ignition switch to OFF. Disconnect battery
negative cable. Remove left instrument cluster bezel
and main cluster assembly. Install a jumper wire
from cavity 2 of cluster connector to a good ground.
Connect battery negative cable. Turn ignition switch
to ON. Lamp should light. If OK, go to next step. If
not OK, replace bulb.(3) Turn ignition switch to OFF. Disconnect battery
negative cable. Unplug cluster connector. Check for
continuity between cavity 2 of cluster connector and
a good ground. There should be no continuity. If OK,
go to next step. If not OK, repair short circuit to
PCM as required.
(4) Check continuity between cavity 2 of cluster
connector and cavity 32 of PCM connector. There
should be continuity. If not OK, repair open circuit to
PCM as required.
SEAT BELT REMINDER LAMP
(1) Refer to Group 8U - Chime/Buzzer Warning
Systems to check chime/buzzer module operation. If
OK, go to next step. If not OK, replace chime/buzzer
module.
(2) Disconnect battery negative cable. Remove left
instrument cluster bezel and main cluster assembly.
Unplug cluster connector. Check for continuity be-
tween cavity 20 of cluster connector and a good
ground. There should be continuity. If OK, plug clus-
ter connector back into cluster and go to next step. If
not OK, repair open circuit to ground as required.
(3) Connect battery negative cable. Install a
jumper wire between a 12-volt battery feed and cav-
ity 16 of cluster connector. Lamp should light. If OK,
go to next step. If not OK, replace bulb.
(4) Disconnect battery negative cable. Unplug
chime/buzzer module from fuseblock module. Unplug
cluster connector. Check for continuity between cav-
ity 16 of cluster connector and a good ground. There
should be no continuity. If OK, go to next step. If not
OK, repair short circuit to chime/buzzer module as
required.
(5) Check continuity between cavity 16 of cluster
connector and cavity for terminal A3 of chime/buzzer
module (Fig. 7) in fuseblock module. There should be
continuity. If not OK, repair open circuit to chime/
buzzer module as required.
Fig. 7 Chime/Buzzer Module Receptacle
JINSTRUMENT PANEL AND GAUGESÐYJ 8E - 33

TURN SIGNAL INDICATOR LAMPS
(1) Disconnect battery negative cable. Remove left
instrument cluster bezel and main cluster assembly.
Probe cavity 20 of cluster connector. Check for conti-
nuity to a good ground. There should be continuity. If
OK, go to next step. If not OK, repair open circuit to
ground.
(2) Connect battery negative cable. Install a
jumper wire from cavity 18 (left indicator) or cavity 7
(right indicator) of cluster connector to a 12-volt bat-
tery feed. Lamp should light. If OK, continue to next
step. If not OK, replace bulb.
(3) Disconnect battery negative cable. Check for
continuity between cavity 18 (left indicator) or cavity
7 (right indicator) of cluster connector and cavity H
(left front turn signal) or cavity J (right front turn
signal) of steering column wiring connector. There
should be continuity. If OK, refer to Group 8J - Turn
Signal and Hazard Warning Systems for further di-
agnosis. If not OK, repair open circuit as required.
UPSHIFT INDICATOR LAMP
(1) Disconnect battery negative cable. Unplug PCM
connector. Connect battery negative cable. Turn igni-
tion switch to ON. Install a jumper wire from cavity
54 of PCM connector (Fig. 5) to a good ground. Lamp
should light. Remove jumper from ground. Lamp
should go off. If OK, refer to Powertrain Diagnostic
Procedures manual to diagnose PCM. If not OK, turn
ignition switch to OFF and go to next step.
(2) Disconnect battery negative cable. Remove left
instrument cluster bezel and main cluster assembly.
Install a jumper wire from cavity 5 of cluster connec-
tor to a good ground. Connect battery negative cable.
Turn ignition switch to ON. Lamp should light. If
OK, go to next step. If not OK, replace bulb.
(3) Turn ignition switch to OFF. Disconnect battery
negative cable. Unplug cluster connector. Check for
continuity between cavity 5 of cluster connector and
a good ground. There should be no continuity. If OK,
go to next step. If not OK, repair short circuit as re-
quired.(4) Check for continuity between cavity 5 of cluster
connector and cavity 54 of PCM connector. There
should be continuity. If not OK, repair open circuit as
required.
CLUSTER ILLUMINATION LAMPS
(1) Check fuse 10 in fuseblock module. If OK, go to
next step. If not OK, replace fuse.
(2) Turn park lamps on at headlamp switch. Rotate
panel dimmer switch thumb-wheel to HI position,
just before interior lamps detent. Check for battery
voltage at fuse 10 in fuseblock module. Rotate panel
dimmer thumb-wheel towards LO position while ob-
serving test voltmeter. Reading should go from bat-
tery voltage to zero volts. If OK, go to next step. If
not OK, repair open circuit to headlamp switch or re-
fer to Group 8L - Lamps to diagnose headlamp
switch.
(3) Disconnect battery negative cable. Remove left
or center instrument cluster bezel and main or gauge
package cluster assembly. Unplug cluster connector.
Connect battery negative cable. Turn park lamps on
at headlamp switch. Rotate panel dimmer thumb-
wheel to HI position, just before interior lamps de-
tent. Check for battery voltage at cavity 21 of main
cluster connector, or cavity 7 of gauge package clus-
ter connector. If OK, go to next step. If not OK, re-
pair open circuit to fuse as required.
(4) Turn park lamps off. Disconnect battery nega-
tive cable. Remove fuse 10 from fuseblock module.
Probe cavity 21 of main cluster connector, or cavity 7
of gauge package cluster connector. Check for conti-
nuity to a good ground. There should be no continu-
ity. If OK, go to next step. If not OK, repair short
circuit as required.
(5) Probe cavity 20 of main cluster connector, or
cavities 1 and 13 of gauge package cluster connector.
Check for continuity to ground. There should be con-
tinuity. If not OK, repair open circuit as required.
8E - 34 INSTRUMENT PANEL AND GAUGESÐYJJ

DIAGNOSIS
WARNING: ON VEHICLES EQUIPPED WITH AN AIR-
BAG, REFER TO GROUP 8M - RESTRAINT SYS-
TEMS BEFORE ATTEMPTING STEERING WHEEL
COMPONENT DIAGNOSIS OR SERVICE. FAILURE
TO TAKE PROPER PRECAUTIONS COULD RESULT
IN ACCIDENTAL AIRBAG DEPLOYMENT AND POS-
SIBLE PERSONAL INJURY.
(1) Inspect fuses (F8 and F16 in PDC on YJ)(11 in
fuseblock module and F14 in PDC on XJ). Replace
fuses, as required.
(2) Remove the horn relay (in the PDC on YJ)(in
the relay center on XJ). See Horn Relay Connec-
tions-XJ (Fig. 1) or Horn Relay Connections-YJ (Fig.
2) and perform the following tests.
²The common feed terminal (30) is connected to
battery voltage and should be hot at all times. If bat-
tery voltage is not present at relay cavity 30, check
circuit to fuse (F16 on YJ)(11 on XJ). Repair as re-
quired.
²The normally closed terminal (87A) is connected to
terminal 30 in the de-energized position, but is not
used for this application.
²The normally open terminal (87) is connected to
the common feed terminal (30) in the energized posi-
tion. This terminal supplies battery voltage to the
horn. There should be continuity between relay cav-
ity 87 and the horn terminal at all times. If not, re-
pair wiring or connections as required.
²The coil battery terminal (86) is connected to the
electromagnet in the relay, and battery voltage
should be present at all times. If battery voltage is
not present at relay cavity 86, check circuit to fuse
(F16 on YJ)(11 on XJ). Repair as required.
²The coil ground terminal (85) is connected to the
electromagnet in the relay. It is grounded when the
horn switch is depressed. Check for continuity to
ground at relay cavity 85 with the horn switch de-
pressed. If no continuity is found with horn switch
depressed or, if continuity is found with horn switch
released, repair horn switch or wiring as required.
See Horn Switch Remove/Install in this group for ser-
vice procedures.
If all relay connections check OK, proceed to next
step.
(3) With the horn relay still removed, check the
horn relay by performing the following tests.
²A relay in the de-energized position should have
continuity between terminal 87A and terminal 30,
and no continuity between terminal 87 and terminal
30.
²Resistance value between terminals 85 and 86
(electromagnet) is 7565 ohms.²Connect a battery to terminals 85 and 86. There
should now be continuity between terminal 87 and
terminal 30.
If relay fails any of the above tests, replace faulty
relay. If relay checks OK, reinstall and proceed to
next step.
(4) Disconnect wiring at horn terminal. Depress
horn switch. There should be battery voltage at the
horn wiring connector. If not, repair wiring to relay.
If OK, proceed to next step.
(5) Measure the resistance between the horn
bracket and a good chassis ground. The meter should
read zero ohms. If not, clean and tighten ground con-
nection between horn mounting screw and bracket. If
OK, replace faulty horn(s).
Fig. 1 Horn Relay Connections-XJ
Fig. 2 Horn Relay Connections-YJ
8G - 2 HORNSJ

SERVICE PROCEDURES
HORN REMOVE/INSTALL
XJ
(1) Raise and support the vehicle.
(2) Remove the front underbody splash shield.
(3) Remove horn mounting bolt and horn (Fig. 3).
(4) Remove wire from horn.
(5) Reverse removal procedures to install.
YJ
(1) Disconnect wire harness connector from the
horn (Fig. 4).
(2) Remove horn and bracket mounting bolt. Horn
and bracket are removed as an assembly.
(3) Reverse removal procedures to install.
HORN SWITCH REMOVE/INSTALL
WARNING: ON VEHICLES EQUIPPED WITH AN AIR-
BAG, REFER TO GROUP 8M - RESTRAINT SYS-
TEMS BEFORE ATTEMPTING STEERING WHEEL
COMPONENT DIAGNOSIS OR SERVICE. FAILURE
TO TAKE PROPER PRECAUTIONS COULD RESULT
IN ACCIDENTAL AIRBAG DEPLOYMENT AND POS-
SIBLE PERSONAL INJURY.
XJ
(1) Disconnect negative cable from battery and iso-
late.
(2) Using a small screwdriver, remove plastic cover
plug from top outer surface of steering wheel hub
(Fig. 5). Exit vehicle and disarm airbag by reaching
through driver's side window and turning arming
screw counter-clockwise to its travel limit. This is
done using an 8mm socket and manual drive. DO
NOT USE POWER-DRIVEN TOOLS.
(3) From back side of steering wheel, remove 4
nuts attaching airbag module to steering wheel. This
is done using a 10mm socket and manual drive. DO
NOT USE POWER-DRIVEN TOOLS.
(4) Remove airbag module from steering wheel.
(5) To access horn switch retaining screws, pry out
trim cover buttons on back of steering wheel spokes
directly behind horn switches. Remove retaining
screws.
(6) Disconnect horn switch wires located in the
lower portion of steering wheel hub cavity and re-
move switches from steering wheel.
(7) Reverse removal procedures to install. Tighten
hardware as follows:
²airbag module nuts-9to11Nzm (80 to 100 in.
lbs.)
²airbag arming screw - not to exceed 1 to 1.5 Nzm
(10 to 15 in. lbs.).
YJ
(1) Disconnect negative cable from battery.
(2) Remove horn button by pulling straight up.
Fig. 3 Horn Mounting - XJ
Fig. 4 Horn Mounting - YJ
JHORNS 8G - 3

WARNING: THE USE OF VEHICLE SPEED CON-
TROL IS NOT RECOMMENDED WHEN DRIVING
CONDITIONS DO NOT PERMIT MAINTAINING ACONSTANT SPEED, SUCH AS IN HEAVY TRAFFIC
OR ON ROADS THAT ARE WINDING, ICY, SNOW
COVERED, OR SLIPPERY.
DIAGNOSIS
Before beginning diagnosis, perform a vehicle road
test to verify reports of speed control system mal-
function. The road test should include attention to
the speedometer. Speedometer operation should be
smooth and without flutter at all speeds.
Flutter in the speedometer indicates a problem
which might cause surging in the speed control sys-
tem. The cause of any speedometer problems should
be corrected before proceeding. Refer to Group 8E -
Instrument Panel and Gauges for speedometer diag-
nosis.
If a road test verifies a system problem and the
speedometer operates properly, check for:
(1) Loose or corroded electrical connections at the
servo. Corrosion should be removed from electricalterminals and a light coating of Mopar MultiPurpose
Grease, or equivalent, applied.
(2) Correct installation of the vacuum check valve
in the hose from servo to vacuum source. The word
VAC on the valve must point toward the vacuum
source.
(3) Loose or leaking vacuum hoses or connections.
(4) Secure attachment of both ends of the speed
control servo cable.
CAUTION: When test probing for voltage or conti-
nuity at electrical connectors, care must be taken
not to damage connector, terminals, or seals. If
these components are damaged, intermittent or
complete system failure may occur.
Fig. 1 Vehicle Speed Control System
8H - 2 VEHICLE SPEED CONTROL SYSTEMJ

SPEED CONTROL SWITCH
WARNING: ON VEHICLES EQUIPPED WITH AN AIR-
BAG, REFER TO GROUP 8M - RESTRAINT SYS-
TEMS BEFORE ATTEMPTING STEERING WHEEL
COMPONENT DIAGNOSIS OR SERVICE. FAILURE
TO TAKE PROPER PRECAUTIONS COULD RESULT
IN ACCIDENTAL AIRBAG DEPLOYMENT AND POS-
SIBLE PERSONAL INJURY.
(1) Disconnect battery negative cable. Remove
speed control switch from steering wheel.
(2) Check speed control switch continuity as shown
in chart (Fig. 2). If OK, reinstall switch. If not OK,
replace switch.
STOP LAMP SWITCH
(1) Unplug the connector at the stop lamp switch.
With the brake pedal released, check switch for con-
tinuity at the switch side of connector (Fig. 3) as fol-
lows:
(a) There should be continuity between the black
and white/pink wires.
(b) There should be continuity between the yel-
low/red and dark blue/red wires.
(c) There should be no continuity between pink
and white wires.(2) With the brake pedal applied, check switch for
continuity at the switch side of connector (Fig. 3) as
follows:
(a) There should be continuity between pink and
white wires.
(b) There should be no continuity between black
and white/pink wires.
(c) There should be no continuity between the
yellow/red and dark blue/red wires.
(3) If the above results are not obtained, check the
stop lamp switch adjustment. If adjustment is OK,
replace faulty switch. Refer to Group 5 - Brakes for
adjustment and service procedures.
VACUUM SUPPLY TEST
(1) Disconnect vacuum hose at the servo and in-
stall a vacuum gauge in the hose.
(2) Start engine and observe gauge at idle. Vacuum
gauge should read at least ten inches of mercury.
(3) If vacuum does not meet this requirement,
check for vacuum leaks or poor engine performance.
SPEED CONTROL SERVO
(1) Check fuse F13 in the PDC. If OK, go to next
step. If not OK, replace fuse.
(2) Turn ignition switch to the ON position. Check
for battery voltage at fuse F13. If OK, go to next
step. If not OK, repair open circuit to ignition switch
as required.
(3) Connect the negative lead of a voltmeter to a
good chassis ground near the servo. Unplug the
4-way connector going to the servo (Fig. 4 or 5). Push
the speed control switch to the ON position. Check
for battery voltage at servo harness connector cavity
Fig. 2 Speed Control Switch Continuity
Fig. 3 Stop Lamp Switch Connector
8H - 6 VEHICLE SPEED CONTROL SYSTEMJ

SERVICE PROCEDURES
SPEED CONTROL SERVO REMOVE/INSTALL
(1) Disconnect battery negative cable.
(2) Disconnect vacuum hose at servo.
(3) Remove 2 nuts on servo cable sleeve.
(4) Pull speed control cable away from servo to ex-
pose cable retaining clip (Fig. 9).
(5) Remove clip attaching cable to servo.
(6) Pull servo away from mounting bracket.
(7) To install, insert servo studs through holes in
sevo mounting bracket.
(8) Block throttle to full open position, align hole
in cable sleeve with hole in servo pin and install re-
taining clip.
(9) Reverse remaining removal procedures to in-
stall. Tighten servo mounting nuts to 6 Nzm (50 in.
lbs.).
SPEED CONTROL SWITCH REMOVE/INSTALL
WARNING: ON VEHICLES EQUIPPED WITH AN AIR-
BAG, REFER TO GROUP 8M - RESTRAINT SYS-
TEMS BEFORE ATTEMPTING STEERING WHEEL
COMPONENT DIAGNOSIS OR SERVICE. FAILURE
TO TAKE PROPER PRECAUTIONS COULD RESULT
IN ACCIDENTAL AIRBAG DEPLOYMENT AND POS-
SIBLE PERSONAL INJURY.
(1) Disconnect negative cable from battery.
(2) From underside of steering wheel, remove
speed control switch mounting screws (Fig. 10).
(3) Pull switches from wheel and unplug connector.
(4) Plug electrical connector into new switches.
(5) Install new switches with 2 screws.
Fig. 9 Servo Cable Remove/Install
Fig. 10 Speed Control Switch Remove/Install -
Typical
JVEHICLE SPEED CONTROL SYSTEM 8H - 9